Heat treating apparatus and heat treating method for sheet-like article

Abstract

To be provided are a heat treatment apparatus having blocking members which block gaps between the side walls of nozzle boxes provided with slit nozzles, whose size in the lengthwise direction is greater than the width of a sheet, and the side walls of a heat treatment chamber, and gas having a uniform velocity fluctuating no more than ±25% in the lengthwise direction of the slit nozzles is blown out of the slit nozzles to subject the sheet to heat treatment, resulting in little unevenness of temperature in the widthwise direction and reduced energy loss, and a heat treatment method using this heat treatment apparatus.

1. A heat treatment apparatus comprising:
 at least a heat treatment chamber having an inlet and an outlet for a sheet in external wall portions at its two opposite ends; 
 a gas inlet part for letting gas, which is a thermal medium, into the heat treatment chamber; 
 a gas outlet part for discharging the gas out of the heat treatment chamber; and 
 carrying means for running the sheet along a linear route connecting the sheet inlet and outlet within the heat treatment chamber, 
 wherein 
 said gas inlet part has nozzle boxes which blow out gas in a slit shape in a direction substantially orthogonal to the running direction of said sheet, whose lengthwise direction is arranged to be substantially orthogonal to the running direction of said sheet, and whose lengthwise size is greater than the width of the sheet, 
 said nozzle boxes blow out gas having a uniformity of gas velocity fluctuating no more than ±25% in the lengthwise direction of the nozzles, 
 said heat treatment chamber has blocking members which are extended between the external walls at the two ends of the heat treatment chamber and block the gaps between the side wall portions of the heat treatment chamber and the side walls of the nozzle boxes, and 
 flow-rectifying lattices whose rate of aperture area is 70% or more, whose aperture pitch P is from 5 to 50 mm and whose height Z satisfies the condition of P≦Z≦10×P are installed within said nozzle boxes. 
 
   
   
     2. The heat treatment apparatus according to  claim 1 , wherein said flow-rectifying lattices are so installed that a minimum distance Y from them to the nozzles be 0.5×P≦Y≦10×P. 
   
   
     3. A heat treatment apparatus comprising:
 at least a heat treatment chamber having an inlet and an outlet for a sheet in external wall portions at its two opposite ends; 
 a gas inlet part for letting gas, which is a thermal medium, into the heat treatment chamber; 
 a gas outlet part for discharging the gas out of the heat treatment chamber; and 
 carrying means for running the sheet along a linear route connecting the sheet inlet and outlet within the heat treatment chamber, 
 wherein 
 said gas inlet part has nozzle boxes which blow out gas in a slit shape in a direction substantially orthogonal to the running direction of said sheet, whose lengthwise direction is arranged to be substantially orthogonal to the running direction of said sheet, and whose lengthwise size is greater than the width of the sheet, 
 said nozzle boxes blow out gas having a uniformity of gas velocity fluctuating no more than ±25% in the lengthwise direction of the nozzles; and said heat treatment chamber has blocking members which are extended between the external walls at the two ends of the heat treatment chamber and block the gaps between the side wall portions of the heat treatment chamber and the side walls of the nozzle boxes, and 
 said nozzle boxes are so arranged as to satisfy the condition of h≦40×D, where D is the slit width of the slit nozzles and h is the distance from the tips of the slit nozzles to said sheet. 
 
   
   
     4. The heat treatment apparatus according to  claim 3 , wherein said nozzle boxes are provided with N slit nozzles, where N is not smaller than 2 but not greater than 29, and are so arranged as to satisfy the condition of N×D≦h≦30×D.